Scale: 1:12. Model showing the plan for relieving the fids of topmast by swivel fid plates, in order that they may be struck easily without slacking the lanyards. The model has been made entirely in wood, stained a dark brown colour and the bottom of the mast is secured to a plain rectangular baseboard. The mast section has a simple crosstree comprised of four timbers and at the top of which is a fid. The topmast sections secured by the fid and crosstree, and is circular in section at the top and square at the bottom. The topmast section has a sheave within it.

Beneath the crosstree the remains of a label has been pinned with a hand written inscription which reads "Presented by John P Wallis Esq. Plymouth Dockyard (The Inventor........Captain Thomas Froude". The remains of a paper label is applied to the baseboard with an illegible hand written inscription.